Coral Bleaching on Guam

Since this original entry, Guam has experienced three more mass coral bleaching events. In 2015, the Eyes of the Reef Marianas (EOR Marianas) was established as a community-based early warning system to invite all ocean users to report coral bleaching and other reef impacts online. Visit eormarianas.org to learn more or to make a report.

The effects of climate change are a rising concern for Pacific Islanders who find themselves on the front lines. The livelihoods of our brothers and sisters on neighboring islands have been impacted through increased occurrences of droughts and king tides. What about here on Guam? Have we felt the effects of climate change yet?

Photo credit: Tammy Jo Anderson-Taft, Guam EPA

The answer is YES! Increased and early coral bleaching is only one of the effects brought on by climate change. What is coral bleaching? Coral bleaching occurs when sea water temperatures are too hot or too cold causing corals to stress and expel their zooxanthellae, a special algae that lives in corals, is their main food source, and gives corals their beautiful color. Corals begin to pale and turn stark white when they’re bleached. But there is hope! Corals can survive and recover, but that can take a long time.

Bleached soft corals in Merizo. Photo taken July 2014

Last year, Guam and CNMI had a significant coral bleaching event. Even more alarming is the fact that Guam and CNMI were seeing early reports of coral bleaching. Local marine biologist usually expect to see paling/ bleaching corals around October, but there were reports as early as August in 2013. GCCRMP members attended an information session on coral bleaching and helped document bleaching corals at our regular monitoring site at the Piti Bomb Holes Marine Preserve. Members learned how to identify coral bleaching and they can report sightings of coral bleaching. Additionally, Roxanna Miller kicked off our first Science Sunday program with a public talk on coral bleaching. She shared photos and tips on how to identify bleaching or paling corals.

This summer only added to concerns from marine biologists and new concerns brought up by community members. This year, there were reports of coral bleaching as early as June. If you’ve been snorkeling at Ypao Beach this summer, you probably saw large colonies of staghorn corals that were very white or pale-looking. Other areas where coral bleaching has been sighted around Guam is Tumon, Piti, Umatac, and also in Merizo. Last Saturday, GCCRMP members started conducted monitoring surveys in soft coral habitat to help quantify soft coral bleaching in Piti. In addition, members have participated in another reconnaissance survey to look for diseased/sick echinoderms, such as sea cucumbers and sea stars. We’ll continue to work with GCCRMP members to do surveys that can help quantify coral bleaching and track recovery of bleached corals.

GCCRMP Member laying quadrat on paling soft coral

Ultimately, more Guam residents are aware of the effects of coral bleaching to our reefs and understanding its connection to climate change. GCCRMP members have shared stories of relatives or neighbors asking “why are the corals white?,” which has given them an opportunity to share what they know about coral bleaching. Want to become a member and help our team collect data? Email gureefmonitoring@gmail.com or message us on Facebook.